I am running fully updated iMovie and El Cap and i just have a 5 minute long video project. It's pretty much this exact problem but my video is WAY shorter obviously. The following is from an Apple support inquiry. NO answer yet. " Dear all, I am tried to export a movie using the share > file options with the following parameters: Video and Audio 1080p Quality: high Compression: best quality The video is 1h 05 min total and the expected final size is 10 GB. Original sources files are .MTS (H264 MPEG-4 AVC 1920x1080 50fps Audio AC3 (A52) 48KHz). I disabled the energy saving settings preventing my iMac to sleep. I have tried to save it on the local HDD (with 700GB free) and on a network SMB share. At the end I always receive the error failed to share and in the details there is just "rendering error 60" (of which I was not able to find any description on the internet). I tried restarting iMovie and rebooting my iMac, nothing changes. During the exporting process a .mp4 file is created and three other temporary files are created as well, but during the export process the .mp4 file is always zero byte and the others are a few KB or a few MB. Most of the times at the end the .mp4 file is zero byte. Below I attach some of the logs before the interruption of the exporting. Any suggestions on how to solve this issue please?" Seriously frustrating. Any help?